FVP: change the method for translating MPIDR values to a linear indices
x3 will be assigned by the folloing instructions.
So the first instruction is not needed any more.
old method:
(ClusterId * FVP_MAX_CPUS_PER_CLUSTER)
+ (CPUId * FVP_MAX_PE_PER_CPU)
+ ThreadId
it should be
(ClusterId * FVP_MAX_CPUS_PER_CLUSTER) * FVP_MAX_PE_PER_CPU
+ (CPUId * FVP_MAX_PE_PER_CPU)
+ ThreadId
which can be simplified as:
(ClusterId * FVP_MAX_CPUS_PER_CLUSTER + CPUId) * FVP_MAX_PE_PER_CPU + ThreadId
Signed-off-by: Wang Feng <feng_feng.wang@spreadtrum.com>
diff --git a/plat/arm/board/fvp/aarch64/fvp_helpers.S b/plat/arm/board/fvp/aarch64/fvp_helpers.S
index 6ea4585..88fcdb1 100644
--- a/plat/arm/board/fvp/aarch64/fvp_helpers.S
+++ b/plat/arm/board/fvp/aarch64/fvp_helpers.S
@@ -178,19 +178,22 @@
ret
endfunc plat_is_my_cpu_primary
- /* -----------------------------------------------------
+ /* ---------------------------------------------------------------------
* unsigned int plat_arm_calc_core_pos(u_register_t mpidr)
*
* Function to calculate the core position on FVP.
*
- * (ClusterId * FVP_MAX_CPUS_PER_CLUSTER) +
+ * (ClusterId * FVP_MAX_CPUS_PER_CLUSTER * FVP_MAX_PE_PER_CPU) +
* (CPUId * FVP_MAX_PE_PER_CPU) +
* ThreadId
- * -----------------------------------------------------
+ *
+ * which can be simplified as:
+ *
+ * ((ClusterId * FVP_MAX_CPUS_PER_CLUSTER + CPUId) * FVP_MAX_PE_PER_CPU)
+ * + ThreadId
+ * ---------------------------------------------------------------------
*/
func plat_arm_calc_core_pos
- mov x3, x0
-
/*
* Check for MT bit in MPIDR. If not set, shift MPIDR to left to make it
* look as if in a multi-threaded implementation.
@@ -205,9 +208,9 @@
ubfx x2, x3, #MPIDR_AFF2_SHIFT, #MPIDR_AFFINITY_BITS
/* Compute linear position */
- mov x4, #FVP_MAX_PE_PER_CPU
- madd x0, x1, x4, x0
- mov x5, #FVP_MAX_CPUS_PER_CLUSTER
- madd x0, x2, x5, x0
+ mov x4, #FVP_MAX_CPUS_PER_CLUSTER
+ madd x1, x2, x4, x1
+ mov x5, #FVP_MAX_PE_PER_CPU
+ madd x0, x1, x5, x0
ret
endfunc plat_arm_calc_core_pos